Findings: Figures 1, 2 and 3. Figure 1 is a sagittal reconstruction demonstrating a small bowel loop extending into a small hernia sac in the anterior abdominal wall, closed arrow. Figure 2 is a coronal reconstruction demonstrating the same LEFT lateral anterior abdominal wall hernia with small bowel extending into the hernia sac, closed arrow. Figure 3 is the axial image demonstrating a hernia extending through the LEFT lateral abdominal wall at the lateral margin of the rectus muscle and the lateral abdominal musculature, closed arrow. Also demonstrated on Figures 2 and 3 are segments of dilated small bowel, curved arrow.
Diagnosis: Spigelian hernia with incarcerated small bowel loop and small bowel obstruction.
Information:
Spigelian hernias are uncommon hernias of the anterior abdominal wall occurring along the lateral margin of the rectus abdominis muscle through a defect in the linea semilunaris, which is the aponeurosis of the internal oblique and transverse abdominal muscles.
Spigelian hernias usually occur in patients who are
1. Multiparous woman with recent weight loss
2. As a result of increased intra-abdominal pressure secondary to heavy lifting, urinary retention, COPD or gastric obstruction
3. Obesity
4. Prior surgery
5. Peritoneal dialysis
6. Congenital
The differential diagnosis depends on the side of herniation but includes: Appendicitis, bowel obstruction, diverticulitis, colitis and rectus muscle hematomas.
Treatment is either by open surgical technique or laparoscopy. All hernias should be treated due to their risk of incarceration, bowel obstruction and strangulation.
References:
Diagnosis and management of Spigelian hernia: A review of literature and our experience.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2699222
Spigelian, Grynfeltt, and Petit Hernia.
http://www.med-ed.virginia.edu/courses/rad/gi/hernias/Spiggrynpet.html
